In the practice of medicine, it frequently is necessary to excise a skin sample from a given skin area. An example of such a procedure is the excising of skin samples in the performance of biopsies.
As is well known, a biopsy is a surgical procedure performed on the skin or other organ to sample tissue structure and cell content, usually to assist in disease diagnosis.
A skin biopsy may be accomplished in different ways. For instance, a scalpel blade may be used to cut into the skin and excise samples of various sizes. This procedure almost always requires suturing the wound edges together.
In the alternative, the biopsy sample may be obtained by slicing or shaving the skin horizontally to remove an elevated portion. This procedure usually does not require suturing.
The method of sampling skin tissue most often used by dermatologists relies upon the use of an instrument called a skin punch. This is a short, pencil-shaped tool having one end in the form of an open cylinder provided with a sharp, cutting blade. The punch is held at its upper, solid end by the thumb and one or two fingers and twirled while it rests on and is pressed lightly into the skin surface. This creates a plug of tissue which can be snipped loose from its underlying attachment and submitted to the laboratory for examination.
The punch biopsy routine may or may not require suturing. If the defect is only 1-3 mm in diameter, natural and unassisted healing usually will be adequate. However, if the defect is larger, suturing will hasten the healing. It also will result in the formation of a less conspicuous scar.
Although widely used, the foregoing procedure has a significant disadvantage. The biopsy punch inherently cuts a circular opening in the skin. When the edges of a circular opening are brought together, the distal portions splay out and pucker to form nipple-like protrusions. The resulting scar is unsightly and cosmetically undesirable.
To overcome this problem, a procedure has been developed which takes advantage of the fact that there exist in the skin variously disposed lines of natural skin tension. These are called "Langer's lines". They may be taken advantage of to create in the skin an elliptical opening rather than a circular one. The elliptical opening is readily amenable to effective suturing procedures.
Accordingly, to carry out the skin sampling procedure a lateral stretching force is applied to the skin in the skin sampling area. This force is applied in the direction perpendicular to the lines of greater tension.
The stretched skin then is incised to make a substantially round cut defining the sample. The stretching force is removed and the sample excised by cutting or snipping it away from the anchoring tissue.
As this is done, the opening in the skin, which originally is circular, becomes elliptical. This is owing to deformation by the lines of tension (Langer's lines) which exist in the skin. As noted, the elliptical opening may be sutured effectively.
However, even this improved technique is characterized by a problem the solution to which is the object of the present invention.
In carrying out a punch biopsy, the surgeon normally stretches the skin in the biopsy area by applying stretching force perpendicular to Langer's lines with the thumb and forefinger of one hand while manipulating the biopsy punch with the other hand. It is the surgeon's intention to maintain the stretching tension for the entire duration of the sampling procedure.
In practice, this may be difficult to do.
First, because of inattention, distraction, fatigue, absorption in his work or other disturbing factors, the surgeon at the critical moment of taking the biopsy sample may relax the skin-stretching pressure or his fingers may slip. As a result, the punched out opening ("defect") in the skin assumes a round configuration rather than the desired elliptical configuration.
Secondly, the surgeon for any of the above reasons may apply the stretching force in a direction other than the desired direction precisely perpendicular to Langer's lines. In either case, the result is the same. The desired elliptical skin opening is not obtained.
It is the primary object of the present invention to provide an appliance for use by an operator performing the above described skin sampling procedure which will maintain the desired lateral pressure and orientation in the skin sampling area even if the finger pressure and/or direction of force are altered. The device is simple in construction, inexpensive, and easily used. It makes foolproof an important procedure which formerly was susceptible to inaccurate performance.
Broadly stated, the skin sample excising appliance of my invention comprises a thin, fairly rigid, flat or slightly convex rectangular or circular body with a center hole. The inferior surface necessarily, and the superior surface preferably, are processed to make them skid resistant when pressure is applied.
To use the appliance, lateral pressure is exerted perpendicular to Langer's lines by the fingers of the hand which later will hold and use the skin incising tool, e.g. the biopsy punch. The appliance is placed between the laterally pressing fingers which establish the intended, ideal orientation and magnitude of pressure.
It then is held down and in place by the non-biopsying hand, thus holding the underlying stretched skin in its desired optimum stretched condition while the skin sample is incised.
If the surgeon's fingers twist or relax, there will result no change in the surgery field, tension or orientation because the appliance by friction will keep the skin stretched, as it was at the time of appliance placement. The desired easily and effectively sutured elliptical opening in the skin accordingly is obtained.